School of Automation, Nanjing University of Science and Technology, Nanjing 210094, China

The traditional active power filter (APF) using inverter technology needs to use electrolytic capacitor bank for energy storage, which has the disadvantages of large size, high price and low reliability. To solve this problem, this paper focuses on the single-phase AC/AC-type APF without DC energy storage unit. The principle of reactive power and harmonic comprehensive compensation based on even-order harmonic modulation (EHM) technology is introduced. The Fourier series method and data fitting method are used to obtain the relationship of frequency and quantity between each even-order modulation term in the duty cycle and odd-order components in the compensation current. A decoupling modulation strategy is proposed for the coupling control of even-order modulation wave, which improves the compensation accuracy and stability of the system. A single-phase comprehensive compensation scheme is designed, and the simulation and experimental results verify the correctness of the theoretical analysis and the feasibility of the proposed strategy.